Objective: To evaluate noninvasive left ventricular myocardial work in patients with chronic aortic regurgitation(AR) and preserved Left ventricular ejection fraction(LVEF) and its changes after aortic valve replacement or repair (AVR). Methods: Fifty-two patients with moderate or severe chronic AR and preserved LVEF treated by AVR in Northern Jiangsu People''s Hospital were included. Noninvasive LV myocardial work indices and global longitudinal strain were measured at baseline and postoperatively (between 2 and 12 months after surgery) and compared with previously reported normal reference ranges. Results: Based on normal reference values, patients with chronic AR and preserved LVEF had preserved or increased values of LV global work index (GWI; 83% and 17%, respectively) and LV global constructive work (GCW; 75% and 25%, respectively) and preserved LV global work efficiency (GWE). Left ventricular GWI and GCW showed a positive correlation with markers of AR severity and parameters of LV systolic function. Left ventricular GWI, GCW, and GWE decreased after AVR (P < .001), without changes in LV global wasted work (P = .28). The postoperative impairment of LV GWI, observed in 28% of patients, was closely associated with reduced LV reverse remodeling. Conclusions: Noninvasive Left Ventricular myocardial may allow better understanding of myocardial function and energetics than afterload-dependent echocardiographic parameters in chronic AR with preserved LVEF.